Cartridge type circuit breaker



Original Filed Feb. 8, 1937 2 Sheets-Sheet 1 Weyl 3 2f 19 .53 M 4l Illu ` INVENTOR. dimm' Hillyzyagm BY 51g www Mama/f my ATTORNEYS Malh 5, 1940 Y J, H. BuRNslDE, 2D 2,192,222

CARTRIDGE TYPE CIRCUIT BREAKER y Original Filed Feb. 8, 1957 2 Sheets-Sheet 2 INVENTOR, Jame'bfmmide, 2nd,

BY @@WM/WQMMM ATTORNEYS Patented Mar. 5, 1940 CARTRIDGE TYPE CIRCUIT BREAKER James H. Burnside, 2nd, New York, N. Y., assignor, by mesne assignments, to Circuit Breakers, lncl New York, N. Y., a corporation of New Application February 8. 1937, Serial No. 124,573 Renewed July 26, 1939 1c claims. (o1. 20o-411s) The present invention relates to circuit breakers and embodies, more particularly, an improved form of circuit breaker which is adapted to be used in a manner similar to the cartridge type fuse, the construction of the breaker being such as to enable it to be used interchangeably with fuses of -the above character. The structure in which the present invention has been embodied, accordingly, will be termed herein a cartridg type circuit breaker.

En circuit breakers of any type, it is a well known fact that the length ci' the gap between the contacts when opened is one ot the iactors which enters into the ability of the circuit breaker- Y tion has been addressed, heretofore, to this Iactor in the design of circuit breakers. Where the circuit breaker is small, this factor becomes the principal limiting factor in determining the rating of the circuit breaker.

With a view toprovlding a circuit breaker which is adapted to be built in small sizes and which is capable ci breaking relatively large currents, the present invention has been designed, and an object of the invention is to provide a mechanism oi this character which is able to interrupt relatively large currents without destructive arcing in the mechanism fi iurther object of the invention is to provide a circuit breaker of the cartridge type wherein the movable breaker element is eiectively controlled and of such character that relatively large currents may be interrupted effectively and without occasicning destructive arcing.

l-i further object of the invention is to provide a circuit-'breaker of the above character wherein the movable breaker element is operated through a free tripping mechanism by means of which manual actuation of the movable element is prevented when the circuit through the breaker is established.

A further object of the invention is to provide a circuit breaker of the above character wherein the releasing mechanism is so positioned as not to be exposed to any arcing which takes place upon the initial opening movement of the movable breaker element.

VA 4further object of the invention is to provide a circuit breaker of the above character wherein the movable breaker element is controlled by a thermal mechanism which is oi' 'such character as to enable the thermal element to be extremely sensitive to all values of current flowing therethrough.

A further object of the invention is to provide a circuit breaker'of 'the above character wherein the construction is such that the effective length of gap between the breaker contacts is increased by reason of the fact that the movable element is in series with two spaced stationary contacts.

Further objects of the invention will `lne/apparent as it is described in further detail in connection with the accompanying drawings, wherein Figure l is a view in longitudinal section drawn on line i--l of Figure 2 and looking in the direction of the arrows, this view showing a circuit breaker of the cartridge type embodied in the `present invention. f

nFigure 2 is a view in transverse section taken on line 2 2 of Figure 1 and looking in the direcl tion o! the arrows.

Figure 3 is .a partial sectional view'taken on line 3-3 oi Figure'l and looking in the direction of the arrows.

Figure l is a view in section taken on line fi-H oi Figure l and/looking in the direction of v the arrows. i' l Figure 5 is a view similar to Figure l, showing the breaker contacts in open position.

Figure 6 is a detail view showing the thermal release mechanism of the device shown in Figure Figure l is a view in side elevation of the elements shown in Figure 6.

Figure t is a view in section, taken on line of Figure 'l and looking in the direction oi the arrows.

Referring to the above drawings, a circuit breaker of the cartridge type is shown as provided with spaced ferrules lll and l I, having end walls I2 and I3, respectively, which close the ends thereof. Within the ierrules i and Il a cylindrical tube il! of insulating material is provided. The ferrules are secured flxedly to this tube and thus constitute. therewith a unitary assembly.

The tube il is formed with a central hollow portion l as shown at Figures 1, 2, 4`and 5, this hollow portion being of irregular shape. The irregular shape of the hollow portion I5 is produced by four 'longitudinal splines or ridges I8 (Figure 2) which form side grooves I'I and I8 (Figures 2 and" 4) and top and bottom grooves I8 and 20 respectively (Figures 1 and 2).

The side grooves I'I and I8 are adapted to receive the respective stationary contacts 2| and 22, contact 2l being connected to ferrule III by means of a contacting strip 23. Each of the stationary contacts 2l and 22 is received within recesses 2d formed within grooves l? and it) order that the contacting surfaces thereof may lie flush with the surfaces of such grooves. in order to permit the stationary contact members to be inserted in the position illustrated in Figure 2, liners 2d are inserted endwise into the position shown in liigure 1i, the cross section of these liners being the same as that of the stationary7 contacts. The manner in which stationary contact 22 is connected in circuit will be described hereinafter.

Centrally of the tube lll is inner tube which is formed "mth upper and lower splines 2%, extending into the respective grooves and The inner tube 2&5 is slotted at in each of the splines in order that a pin may be slidably received therein. The inner tube is formed vl/'ith cylindrical hollow portion axially theren oi in order that a plug 'be slidably received therein. Plug is secured to the pin as will be eaclily apparent in Figure l. A spring is seated against end wall l2 of i-errule lil and normally urges the plug izll to the right as viewed in Figure i.

About the outer periphery oi the inner tubeA upon the uppor lower splines of the tube. The contact ring is also 'formed with. latn `eral contact members dal and which slide :in the respective grooves il and l and cooperate with the respective stationary contacts lll and to establish contact therebetween when the elements are in the position shown in Figure 1. The contacts 34 and 35 are provided with graphite inserts 36 upon the ends thereof where the elecu trical circuit is broken, these inserts cooperating with stationary inserts 3l on the respective stationary contacts 2l and 22 in order that destructive arcing may be avoided.

Inasmuch as the contact ring 32 is secured to the pin 28, spring 3| serves as a means for opening the circuit between the stationary contacts. Motion of the pin 28 to the left, as viewed in Figure l, is effected by means of a manually operated slide member 38 which is provided at the ends thereof with linger members 39. The slide 38 is received within slots` 40, formed in the upper portion of the tube I4. Within the upper portion of tube I4 there is provided a hollow portion 4l which communicateswith the upper slot I9. A leaf spring 42 is secured to the slide 38 andds formed with an aperture` 43 within which the upper end of pin 28 is adapted .to be received. The spring 42 is formed with a rounded nose which facilitates the riding over and 'engagement of the spring 42 with the pin 28, in which condition the pin 28 may be advanced to the left, as viewed in Figure 1 and against the action of the spring 3l.

The pin 28 is held in the closed position shown in 4 Figure 1 by means of a bimetallic latch band 45 which is secured to the outer tube I4 by means of rivets 46 and at the end of the hollow portion 4l adjacent the stationary contacts 2| and 22.

The end of the bimetal element 45 is formed with spaced fingers 41 which are adapted to engage recesses 48 formed in the upper end of pin4 2li. In order that the fingers 41 may secure the pin in the positions shown, the recesses 48 are 4formed escasa-'s with detents fl@ having sloping cam faces titl in order that the fingers fill may ride upwardly thereon and snap into engagement behind the de tents L39.

in order that the connection between the spring l2 and pin 28 may be broken when the circuit is established to protdde for a free tripping operation, the spring (l2 rides up a cam surface and is disengaged from the pin after the fingers il? have engaged behind the detente 1li?. instant the electrical circuit has not yet been established by reason of fact that the circuit from the 'other stationary contact i2 to the ier rule l l Ln-des a sliding contact member l which is carried by manually slidable member Sil. This sliding Contact member rides upon acontact sti p which is in Contact with the end ierrule il and engages the upwardly extending l the bimetal member l5 only alter the spring il has disengaged the pin rline circuit between the bimetal member l5 and the stationm ary contact il@ is established by means oi' a pgtail connection iithen the circuit is closed by means oi the above construction, current flows between ier rules and l t through the Contact strip t lich is connected to ferrule lll. stationary contact ill,

"able Contact il Contact ring movable con'- om, stationary contact pigtail i, bimetal f1, este' sion il o to the errule i l.

'low through the bimetal elen ig the movable contacts di and trom lectivo stationary contacts 2l thus arc betv een the respective gra,

ol U d sultinrJ o l and .no 'which are mounted upon the respective movable and stationary contacts. inasmuch as the spring 3i is received within the inner tube 2E and the slots 2l yin such tube are angularly spaced 90 with respect to the Contact members, any destructive effect of the arc upon the spring is reduced to a minimum. Moreover, the inner tube effectively spaces the respective contacts to prevent arcing over during the opening of the breaker.. The foregoing construction enables the greatest portion of the length of the device to be utilized in breaking the circuit inasmuch as the movable contacts move with the pin 28 which moves practically to the end of the device. In order that the sliding contacts 52 may be urged against the contact strip 53 and bimetal end 54 eiectively, the left hand end of spring 42 is extended upwardly to form va spring member 5E which engages against the stationary tube I4 as will be readily seen in'igure 1`.

I claim:

l. A circuit breaker comprising an elongated insulating member having a terminal at each end thereof, spaced stationary breaker contacts Within the' said member adjacent one end thereof, means to connect one of said contacts to the adiacent'terminal, a, movable contact member, means to urge the movable member into an open position, means to hold the movable member re leasably in a closed position, means to release the holding means, means connecting the other of the said stationary contacts to the other terminal, and means in the last named connection to actuate the releasing means upon existence of an excess current.

2. A circuit breaker comprising an elongated insulating member having a terminal at each At this l 'l thereof, sliding Contact 'w l :member Contact s iii end thereof, said member being hollow and having spaced contacts formed therein adjacent one end thereof, means to connect one of the contact-s to the adjacent terminal, an insulating tube within the rst member and spaced between the contacts, a movable contact member slidable on the tube, and means to connect the other stationary contact with the other terminala'I 3. A circuit breaker comprising an elongated insulating member having a terminal at each end thereof, said member being hollow and having spaced contacts formed therein adjacent one end thereof, means to connect one of the contacts to the adjacent terminal, an insulating tube within the rst member and spaced between the contacts, a movable contact member slidable on the tube, means to connect the other stationary contact with the other terminal, and means within the tube to urge the movable member into an open position.

4. A circuit breaker comprising an elongated insulating member having a terminal at each end thereof, said member being hollow and having spaced contacts formed therein adjacent one end thereof, means to connect one of the contactsto the adjacent terminal, an insulating tube within the iirst member and spaced between the contacts, a movable contact member 'slidable on the tube, means to connect the other stationary contact with the other terminal, means within the tube to urge the movable member into an open position, and cooperating splines and grooves formed in the tube and rst named member.

5. A circuit breaker comprising an elongated insulating member having a terminal at each end thereof, said member being hollow and having spaced contacts formed therein adjacent one end thereof, means to connect one of the contacts lto the adjacent terminal, an insulating tube within the ilrst member and spacedbetween the contacts, a movable contact member slidable on the tube, means to connect the other stationary contact with the other terminal, means within the tube to urge the movable member into an open position, splines on the first named member forming diametrically. spaced side grooves in which the stationary contacts are positioned, and extensions on the movable contact member received within the said grooves and formed with contacting portions engaging the stationary contacts therein.

6. A circuit breaker comprising an elongated insulating member having a terminal at each end thereof, said member being hollow and having spaced contacts formed therein adjacent one end thereof, means to connect one of the contacts to the adjacent terminal, an insulating tube within the iirst member and spaced between the contacts, a movable contact member slidable on the l tube, means to connect the other stationary contact with the other terminal, a disc slidable Within the hollow tube and connected to the movable contact member, and a spring in the tube engaging the disc to urge the contact member into an open position. y

'7. A circuit breaker comprising spaced stationary breaker contacts, a movable member having contact portions engaging the` respective stationary contacts, means to urge the movable member into an open position, bimetal means to hold the movable member in a closed position, manually operable means to move the movable member into engagement with the bimetal means, and means to close an electrical circuit between the stationary contacts subsequent. to the said engagement.

8. A circuit breaker comprising spaced stationary breaker contacts, a movable member having contact portions engaging the respective stationary contacts, means to urge the movable member into an open position, bimetal means to hold the movable member in a closed position,y

manually operable means to move the movable member into `engagement with the bimetal means, and means on the manually operable means to close an electrical circuit between the stationary contacts subsequent to the said engagement.

9. A circuit breaker comprising spaced stationary breaker `lcontacts, a movable member having contact portions engaging the respective stationary contacts, means to urge the movable member into an open position, bimetal means to hold the movable member in a closed position,

manually operable means to move the movable member into engagement with the bimetal means,

and means on the manually operable means to.

movable member into circuit closing position,

and means on the manual member to connect the bimetal means to the other terminal after the movable member is engaged by the bimetal means. l

1l. A circuit breaker comprising an elongated member having a terminal at each end thereof, spaced stationary breaker contacts adjacent one end thereof, means to connect one o f said contacts to the adjacent terminal, a movable contact member, means to urge the movable member into an open position, 4bimetal means connected to the other stationary contact to hold the movable member releasably in a closed position, a manually operable member to move the movable member into circuit closing position, means to disengage the manually operable member from' the movable member after engagem *"'toi the said movable member by the bime 'l"'means,

and means on the manual member to connect the bimetal means to the other terminal after the manual member has been disengaged from the movable member.

12. A circuit breaker comprising an elongated member formed with a central hollow portion and a hollow portion above the central p ortio'n, 'f

a terminal at each end of the elongated member, spaced stationary breaker contacts adjacent one end of the elongated member, means to connect one of the stationary contacts to the ad jacent terminal, a movable contact member slidably mounted in the central hollow portion of the elongated member, means to urge the movable member into an open position, manually operable means slidable in the second hollow portion to move the movable member into closed position, and means inthe last named hollow portion to release the movable member.

JAMES H. BURNSIDE. 2ND. 

